Prediction method for thermal deformation dynamic parameters of GH4169 alloy aviation die forging

Abstract

The invention provides a GH4169 alloy aviation die forging thermal deformation dynamic parameter prediction method comprising the following steps: S1, before die forging production, carrying out numerical simulation analysis; s2, performing full-process simulation on the thermal deformation process of the forge piece; s3, regulating and controlling the forming state of simulation deformation through a method of regulating deformation parameters, and changing a final simulation result; s4, according to the material constitutive model, the dislocation density model and the dynamic recrystallization kinetic model of the GH4169 material, accurate simulation of the thermal deformation process is established; and S5, in the thermal deformation process, different lubrication modes are adopted to control deformation friction factors, and finally dynamic control and detection of thermal deformation of the die forging are achieved. And S6, the final strain of the GH4169 die forging is dynamically monitored, regulated and controlled. Through the dynamic coupling relation between the shear friction factor and the deformation rolling reduction and the forging strain field, the thermal deformation dynamic parameters of the GH4169 die forging can be accurately predicted.

Description

Technical Field

[0001] The invention relates to the technical field of alloy die forging prediction models, in particular to a method for predicting dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings. Background Art

[0002] With the development of China's aviation industry, the thrust-to-weight ratio of aircraft engines has continued to increase, and the service environment of key components such as engine rotors, blades, and high-pressure turbine disks has become extremely harsh, and the performance requirements for key components have become stringent; aircraft engines, as the "heart" of aircraft and rockets, directly affect the development and progress of my country's aviation industry; however, with the improvement of engine and rocket efficiency and lightweight, higher requirements are placed on the strength, toughness, oxidation resistance, acid and alkali corrosion resistance, and wear resistance of key load-bearing components; therefore, how to improve the comprehensive performance of key load-bearing components has always been a focus of concern for many scholars.

[0003] At present, the preparation of large-scale aviation die forgings is mainly carried out in combination with fixed parameters and industry standards, but the fixed thermal deformation parameters cannot meet the dynamic change trend in the actual production process; at the same time, a single deformation parameter cannot meet the requirements of large-scale aviation die forgings for microstructure and performance; generally speaking, the mechanical properties and microstructure of GH4169 alloy aviation die forgings are affected by the dynamic coupling relationship between the strain, strain rate and deformation temperature during the forging process; such as the Arrhenius hyperbolic sine constitutive model, which is an important model for studying the rheological behavior of metal materials and can reflect the complex nonlinear relationship between rheological stress, strain rate and temperature; this prediction model needs The constant temperature condition is sought, and the influence of friction factors on the deformation process is not considered. However, the influencing factors of GH4169 alloy aviation die forgings far exceed the prediction model. In the actual production process, due to comprehensive factors such as environment, cost, economic benefits and feasibility, it is impossible to achieve absolute constant temperature deformation. The thermal deformation process of forgings is often accompanied by multi-factor and multi-factor dynamic coupling relationships. The deformation resistance of GH4169 alloy is large, and the forming tonnage of forgings is high, so the influence of friction factors on the body of forgings cannot be ignored. The friction factor is mainly determined by the auxiliary materials between the die and the forging. By changing the auxiliary materials between the die and the forging (such as insulation cotton, fiber cloth, graphite, etc.), the shear can be adjusted on the one hand. Friction factor; on the other hand, it can further improve the deformation structure and reduce the deformation resistance; because there is a large temperature gradient between the contact surface of the die and the forging during the actual forging process, the temperature of the forging surface drops rapidly, forming a cold film layer on the forging; the formation of the cold film layer cannot be eliminated, but an excessively thick cold film layer will affect the forging body, causing the forging structure to have mixed crystals, necklace structures, and undeformed high dislocation original structures. Such structures are extremely unstable under complex service conditions and are prone to stress concentration and crack sources, reducing the service life of the forging; therefore, adjusting the friction factor between the forging and the die can not only improve the metal flow ability during the forging forming process, but also improve the temperature drop during the forging forming process. Reduce the cold layer; in addition, under low temperature conditions, there will be hysteresis in the deformation process of the forging, resulting in insufficient deformation, unable to completely fill the mold cavity, and reducing the qualified rate of forgings; deformation hysteresis will make the deformation of the forging fail to reach the expected deformation amount, resulting in insufficient material deformation; when the cold layer is thicker, the flow rate between the forging and the mold and the flow between the forgings are quite different, and shear deformation occurs inside the forging; shear deformation will cause a large amount of deformation heat in the forging; the generation of deformation heat causes the temperature of the core of the forging to rise rapidly, causing the originally required fine equiaxed recrystallized structure to grow further, lose the equiaxed characteristics and reduce the mechanical properties of the forging; when the temperature is too high, the core of the forging may overheat or overburn, resulting in the scrapping of the forging. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for predicting the dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings. The method can accurately predict the dynamic parameters of thermal deformation of GH4169 die forgings through the dynamic coupling relationship between the shear friction factor and the deformation reduction and the strain field of the forging.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] The prediction method of hot deformation dynamic parameters of GH4169 alloy aviation die forgings includes the following steps:

[0007] S1. Before the production of GH4169 alloy die forgings, numerical simulation analysis is first carried out, combining the constitutive model, recrystallization model, dislocation density model of GH4169 alloy, and the transit time t, air heat transfer coefficient δ1, contact heat transfer coefficient δ2, deformation temperature T, initial grain size D0, friction factor λ and deformation Δ parameters during thermal deformation; the forging process, stress, strain state and microstructural transformation law of GH4169 forgings are analyzed;

[0008] S2. Simulate the entire thermal deformation process of the forging; set the basic parameters of the deformation process according to the actual production process and the heat transfer rate of the GH4169 material; evaluate the simulation results based on the existing parameters to obtain the microstructure and corresponding mechanical properties under the corresponding thermal deformation parameters;

[0009] S3. When the existing parameters cannot meet the mechanical properties and microstructure requirements of GH4169 forgings, the forming state of simulated deformation is adjusted by adjusting the deformation parameters to change the final simulation results; the deformation parameters are dynamically adjusted by adjusting the deformation state during the actual thermal deformation process to predict the microstructure morphology and mechanical properties of forgings with different deformation parameters;

[0010] S4, by adjusting the friction factor λ and the deformation amount Δ during the thermal deformation process, different strain sizes of the die forging at the same forging temperature are obtained;

[0011] S5. By measuring the friction factor of different lubricants during thermal deformation, different lubrication methods are used to control the deformation friction factor during thermal deformation, and finally the dynamic control and detection of thermal deformation of die forgings are realized;

[0012] S6. Through the dynamic coupling relationship between the friction factor and deformation and the strain of the forging, the strain of the GH4169 die forging is dynamically monitored and regulated, and finally the microstructure state and mechanical properties of the GH4169 alloy forging are predicted.

[0013] In step S2, the basic parameters include the transport time t, the air heat transfer coefficient δ1, the contact heat transfer coefficient δ2, the deformation temperature T, the initial grain size D0, the friction factor λ and the deformation amount Δ parameter.

[0014] In step S2, the thermal deformation process of the forging includes a transfer heat convection process, a heat conduction process of the forging on the die, and a deformation pressing process.

[0015] In step S6, the dynamic coupling relationship between the friction factor, the deformation and the forging strain is shown in formula (1);

[0016]

[0017] In formula (1), ε is strain; λ is friction factor; Δ is deformation; a, b, c, α, β are constants;

[0018] The experimental parameters of different deformations and different friction factors are fitted to obtain formula (II), as follows:

[0019]

[0020] The experimental parameters of different deformations and different friction factors are fitted as follows:

[0021] When the forging deformation is less than 61%, the forging strain is affected by the deformation Δ, at which time β = 0, α = 1, and the change of the friction factor has little effect on the strain;

[0022] When the deformation of the forging is greater than 61%, the strain of the forging is affected by the deformation Δ and the friction factor λ. At this time, β=1, α=0, and the friction factor has a greater influence on the strain of the forging.

[0023] The beneficial effects of the present invention are:

[0024] 1. During the hot deformation process, the dynamic parameters of the hot deformation process of GH4169 alloy die forgings are predicted and analyzed through the dynamic coupling relationship between the shear friction factor and the strain and the strain field of the forgings; by adjusting the shear friction factor and the hot deformation reduction, forgings with excellent mechanical properties and uniform and stable microstructure are obtained, thereby improving the service life of the forgings; by adjusting the deformation parameters, the forging structure can be accurately predicted, the internal microstructure morphology of the forgings can be precisely controlled, and a theoretical basis can be provided for adjusting the mechanical properties of forgings in actual production.

[0025] 2. By fitting the experimental parameters of different deformation amounts and different friction factors, the required strain can be accurately predicted and regulated, the final strain size of the GH4169 die forgings can be dynamically monitored, and rapid control of the forgings of GH4169 materials can be achieved, the simulation design and analysis links can be eliminated, the product development cycle can be greatly shortened, and the product yield rate can be improved; the product scrap rate can be reduced, the performance stability of forgings can be improved, the service life can be increased, and energy consumption can be greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the fitting curve diagram of friction factor and strain;

[0027] Figure 2 Fitting curve of friction factor and strain at small strain;

[0028] Figure 3 It is the fitting curve diagram of deformation and strain;

[0029] Figure 4 It is the fitting curve diagram of deformation, friction factor and strain. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0031] Example 1

[0032] The prediction method of hot deformation dynamic parameters of GH4169 alloy aviation die forgings includes the following steps:

[0033] S1. Before the production of GH4169 alloy die forgings, numerical simulation analysis is first carried out, combining the constitutive model, recrystallization model, dislocation density model of GH4169 alloy, and parameters such as transit time t, air heat transfer coefficient δ1, contact heat transfer coefficient δ2, deformation temperature T, initial grain size D0, friction factor λ and deformation amount Δ during thermal deformation; the forging process, stress, strain state and microstructural transformation law of GH4169 forgings are analyzed;

[0034] S2. Simulate the entire thermal deformation process of the forging; set the basic parameters of the deformation process according to the actual production process and the heat transfer rate of the GH4169 material; evaluate the simulation results based on the existing parameters to obtain the microstructure and corresponding mechanical properties under the corresponding thermal deformation parameters;

[0035] S3. When the existing parameters cannot meet the mechanical property requirements and microstructure requirements of GH4169 forgings, the deformation parameters are adjusted to control the forming state of the simulated deformation and change the final simulation results. For example, the deformation amount Δ is generally adjusted by changing the deformation height or deformation mode, and the friction factor can be adjusted by changing the contact conditions between the die and the forging or by changing the lubricating medium. Different lubricating media and deformation heights are used in the thermal deformation process to finally realize the dynamic control and detection of the thermal deformation process of the die forging. Therefore, the deformation parameters are dynamically adjusted by adjusting the deformation state in the actual thermal deformation process to predict the microstructure morphology and mechanical performance of the forgings with different deformation parameters.

[0036] S4. By adjusting the friction factor λ and the deformation Δ during the thermal deformation process, different strain sizes of the die forgings at the same forging temperature are obtained; and the strain size directly affects the microstructure and mechanical properties of the forgings. Therefore, adjusting the friction factor and the deformation amount can regulate the microstructure state and the excellent degree of mechanical properties of the GH4169 alloy; by adjusting the friction factor and the deformation size during the thermal deformation process, the die forgings show different strain change trends at the same forging temperature, and the strain change trend conforms to formula (II);

[0037] S5. By measuring the friction factor of different lubricants during thermal deformation, different lubrication methods are used to control the deformation friction factor during thermal deformation, and finally the dynamic control and detection of thermal deformation of die forgings are realized;

[0038] S6. Through the dynamic coupling relationship between the friction factor and deformation and the strain of the forging, the strain of the GH4169 die forging is dynamically monitored and regulated, and finally the microstructure state and mechanical properties of the GH4169 alloy forging are predicted.

[0039] In step S2, the basic parameters include the transport time t, the air heat transfer coefficient δ1, the contact heat transfer coefficient δ2, the deformation temperature T, the initial grain size D0, the friction factor λ and the deformation amount Δ parameter.

[0040] In step S2, the thermal deformation process of the forging includes a transfer heat convection process, a heat conduction process of the forging on the die, and a deformation pressing process.

[0041] In step S6, the dynamic coupling relationship between the friction factor, the deformation and the forging strain is shown in formula (1);

[0042]

[0043] In formula (1), ε is strain; λ is friction factor; Δ is deformation; a, b, c, α, β are constants;

[0044] The experimental parameters of different deformations and different friction factors are fitted to obtain formula (II), as follows:

[0045]

[0046] The experimental parameters of different deformations and different friction factors are fitted as follows:

[0047] When the deformation of the forging is less than 61%, the fitting slope of the friction factor and the strain is close to 0, so the effect of the friction factor on the strain of the forging can be ignored. The strain of the forging is affected by the deformation Δ. At this time, β=0, α=1, and the change of the friction factor has little effect on the strain.

[0048] When the deformation of the forging is greater than 61%, the strain of the forging is affected by the deformation Δ and the friction factor λ. At this time, β=1, α=0, and the friction factor has a greater influence on the strain of the forging.

[0049] The dynamic coupling relationship between the shear friction factor, the deformation reduction and the strain field of the forging can be used to accurately predict the dynamic parameters of the hot deformation of the GH4169 die forging. By adjusting the shear friction factor and the reduction, the strain suitable for the material can be obtained, and forgings with excellent mechanical properties can be obtained, thereby increasing the service life of the forgings. Experiments with different reductions are carried out at different positions of the forging, and a polynomial is fitted to the experimental data.

[0050] The experimental parameters of different deformations and different friction factors are fitted as follows:

[0051] like Figure 2 As shown in the figure, when the deformation is less than 61%, the fitting curve of the friction factor and the strain is close to 0. Therefore, the influence of the friction factor on the strain of the forging can be ignored. The strain of the forging is mainly affected by the deformation Δ. At this time, β=0, α=1, and the change of the friction factor has little effect on the strain.

[0052] When the deformation of the forging is greater than 61%, the strain of the forging is mainly affected by the deformation Δ and the friction factor λ. At this time, β=1, α=0, and the friction factor has a greater influence on the strain of the forging.

[0053] When the deformation is greater than 61%, the average value of the fitting slope of the friction factor and the strain is 0.69, so the friction factor has a greater influence on the strain.

[0054] Combining the data of different friction coefficients and deformation amounts, the fitting curve of friction factor and strain is obtained (such as Figure 1 The average value of the correlation coefficient R2 is 0.99, and the fitting curve of deformation and strain (as shown in Figure 3The average value of the correlation coefficient R2 is 0.97, and the fitting curve of deformation, friction factor and strain (as shown in Figure 4 As shown), the correlation coefficient R2 = 0.99; it can be seen that the fitting correlation of each curve is high. Therefore, formula (II) can better predict the dynamic coupling relationship between friction factor, deformation and strain during the hot deformation process of GH4169 alloy.

[0055] The deformation parameter control of GH4169 alloy die forgings is single and cannot meet the complex actual production needs, resulting in the inability to accurately predict the microstructure of the forgings and unstable mechanical properties. During the hot deformation process, the dynamic parameters of the hot deformation process of GH4169 alloy die forgings are predicted and analyzed through the dynamic coupling relationship between the shear friction factor and the strain and the strain field of the forging. By adjusting the shear friction factor and the hot deformation reduction, forgings with excellent mechanical properties and uniform and stable microstructure are obtained, thereby improving the service life of the forgings. By adjusting the deformation parameters, the forging structure can be accurately predicted and the internal microstructure morphology of the forging can be precisely controlled, providing a theoretical basis for adjusting the mechanical properties of forgings in actual production.

[0056] By fitting the experimental parameters of different deformation amounts and different friction factors, the required strain can be accurately predicted and regulated, the final strain size of GH4169 die forgings can be dynamically monitored, and rapid control of GH4169 material forgings can be achieved. The simulation design and analysis links can be eliminated, the product development cycle can be greatly shortened, and the product yield rate can be improved; the product scrap rate can be reduced, the performance stability of forgings can be improved, the service life can be increased, and energy consumption can be greatly reduced.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The prediction method of dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings is characterized by: The following steps are involved: S1. Before the production of GH4169 alloy die forgings, numerical simulation analysis is first carried out, combining the constitutive model, recrystallization model, dislocation density model of GH4169 alloy, and the transit time t, air heat transfer coefficient δ1, contact heat transfer coefficient δ2, deformation temperature T, initial grain size D0, friction factor λ and deformation Δ parameters during thermal deformation; the forging process, stress, strain state and microstructural transformation law of GH4169 forgings are analyzed; S2. Simulate the entire thermal deformation process of the forging; set the basic parameters of the deformation process according to the actual production process and the heat transfer rate of the GH4169 material; evaluate the simulation results based on the existing parameters to obtain the microstructure and corresponding mechanical properties under the corresponding thermal deformation parameters; S3. When the existing parameters cannot meet the mechanical property requirements and microstructure requirements of GH4169 forgings, the forming state of simulated deformation is regulated by adjusting the deformation parameters to change the final simulation results; By adjusting the deformation state during the actual thermal deformation process, the deformation parameters can be adjusted dynamically to predict the microstructure morphology and mechanical properties of forgings with different deformation parameters; S4, by adjusting the friction factor λ and the deformation amount Δ during the thermal deformation process, different strain sizes of the die forging at the same forging temperature are obtained; S5. By measuring the friction factor of different lubricants during thermal deformation, different lubrication methods are used to control the deformation friction factor during thermal deformation, and finally the dynamic control and detection of thermal deformation of die forgings are realized; S6. Through the dynamic coupling relationship between the friction factor and deformation and the strain of the forging, the strain of the GH4169 die forging is dynamically monitored and regulated, and finally the microstructure state and mechanical properties of the GH4169 alloy forging are predicted.

2. The method for predicting the dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings according to claim 1, characterized in that: In step S2, the basic parameters include the transport time t, the air heat transfer coefficient δ1, the contact heat transfer coefficient δ2, the deformation temperature T, the initial grain size D0, the friction factor λ and the deformation amount Δ parameter.

3. The method for predicting the dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings according to claim 1, characterized in that: In step S2, the thermal deformation process of the forging includes a transfer heat convection process, a heat conduction process of the forging on the die, and a deformation pressing process.

4. The method for predicting the dynamic parameters of thermal deformation of GH4169 alloy aviation die forgings according to claim 1, characterized in that: In step S6, the dynamic coupling relationship between the friction factor, the deformation and the forging strain is shown in formula (1); In formula (1), ε is strain; λ is friction factor; Δ is the deformation; a, b, c, α, β are constants; The experimental parameters of different deformations and different friction factors are fitted to obtain formula (II), as follows:

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